macro
boot.janet on line 658, column 1
(if-let bindings tru &opt fal)
Make multiple bindings, and if all are truthy, evaluate the `tru`
form. If any are false or nil, evaluate the `fal` form. Bindings
have the same syntax as the `let` macro.
(if-let [x true
y (not (not x))]
:a
:b)
# => :a
(if-let [x true
y (not x)]
:a
:b)
# => :b